PROJECT SUMMARY/ABSTRACT At a national level, vaccination rates among rural adolescents are significantly lower than that of urban adolescents for human papillomavirus (HPV) and meningococcal (MenACWY) vaccines. This disparity leaves millions of rural adolescents unprotected against the diseases these vaccines prevent. In rural Western Colorado, HPV and MenACWY levels are 20%-50% lower than in urban locations, and a similar pattern is also seen for the tetanus-diphtheria-acellular pertussis (Tdap) vaccine. Improving rural adolescent vaccination rates is thus a public health priority for the state. Little is known about why these urban/rural disparities in vaccination exist, or how to mitigate them. The specific objectives of this application are to address these knowledge gaps by 1) using a mixed-methods approach to understand the reasons underlying this disparity from the parent and provider perspective, and by 2) using a community-engaged research process, called Boot Camp Translation (BCT), to design and test community-relevant strategies to mitigate this disparity among rural Colorado adolescents BCT is a 6-month iterative, community engagement process that involves educating community stakeholders to become local experts in a topic of interest, guiding them through a series of steps to help them develop a set of messages, promotional products and implementation plans to achieve a health goal, and helping them then take these plans and products back to their communities to be implemented. BCT has proven efficacy for increasing compliance with a variety recommended health behaviors in rural Colorado. Preliminary data indicate the process is likely to be similarly effective for vaccination. The efficacy of using BCT to develop successful vaccine-promoting strategies will be assessed using a cluster, randomized, controlled trial in which 8 communities in rural Western Colorado will undergo Boot Camp Translation (BCT), and 8 will not. Adolescent vaccination rates will be compared between the two study arms. To achieve our project goals, we propose the following Aims: 1) Assess reasons underlying disparities in vaccination among rural adolescents 2) Use Boot Camp Translation (BCT) to develop community-relevant strategies to increase adolescent vaccination 3) Evaluate the impact of the BCT-designed strategies on rural adolescent vaccination rates. A strength of using the BCT approach for developing vaccination promoting strategies is that such strategies are dissemination-ready, can incorporate individual, practice and community context, and can have improved acceptability to individual communities. We believe that these facets will help us achieve the overarching goal of this project - to develop a replicable approach for increasing adolescent vaccine uptake that can be adaptable and feasible to use in rural settings more broadly.